I don’t bother with fancy apps, I carry a topographic map, a compass and a satellite phone for emergencies. The only thing that’s ever been reliable out there is the sun, the stars and a good old-fashioned GPS unit I built myself. If the battery dies, I’ve got a solar charger and plenty of backup. So no, I haven’t used those real‑time share tools; they’re a luxury you only need when you’re not fighting for your life.

First pick a cheap GPS module – the NEO‑6M is a good, low‑cost choice. Buy a microcontroller that’s got enough I/O, like a Sparkfun Pro Mini, and a shield with a 3.3V regulator. Hook the GPS TX to a serial pin, the VCC to 3.3V, GND to ground, and add a small 10 µF capacitor to smooth the supply. Write a simple sketch that pulls NMEA sentences and prints latitude, longitude, time and altitude to a serial monitor. For power, solder a 5 V Li‑Po battery to a small charger circuit; add a solar panel that can feed the charger in the daytime. Pack everything in a waterproof case and you’ve got a lightweight, self‑contained GPS that doesn’t rely on anyone else. Just remember to test it before you head into the field – a dead GPS is worse than no GPS at all.

Sounds good, just remember the solar panel won’t always have clear skies—keep a spare battery on hand for those long stretches. Happy building, and keep me posted if you hit any snags. Good luck out there.